Cell-substratum and cell-cell interactions are central to many biological phenomena. Knowledge of these interactions is crucial to understanding many fundamental biological questions and to designing medical devices. Tissue engineering is an example where control of these interactions is essential to the creation of functional engineered-tissues. Other biomedical applications would range from design of medical implants with targeted tissue response to development of cellular biosensors. Cell-substratum interaction is influenced by topographical in addition to chemical cue. The majority of these studies have been conducted on micropatterned surfaces. Cells clearly respond to the topology of substrates in the micron range in terms of adhesion, proliferation, migration, and gene expression. However, cells in vivo interact with extracellular matrix components in the nanometer scale. For example, the basement membrane of many tissues displays features of pores, fibers, and ridges in the nanometer range. It is thus important to engineer nanostructures to elucidate the response of cells at the nanoscale. We have developed techniques that can produce nanostructures suitable for this purpose using a reversal imprinting technique. We have also used this reversal imprinting technique to imprint over a patterned substrate, thereby creating multi-layer polymer structures with nanoscale features. The overall objective of this proposal is therefore to exploit the recently developed nanopatterning techniques for studying cell-substrate and cell-cell interactions and for creating advanced tissue engineering scaffolds. It is expected that findings from these studies will enhance the fundamental understanding of the important biological processes of cell-substrate and cell-cell interactions, and create the next generation of biomaterials with well-defined nanotopology.